1. Field
The subject matter disclosed herein relates to electronic devices, and more particularly to methods, apparatuses and articles of manufacture for use by one or more electronic devices supporting mobile device positioning within an indoor environment.
2. Information
As its name implies, a mobile device may be moved about, e.g. typically being carried by a user and/or possibly a machine. By way of some non-limiting examples, a mobile device may take the form of a cellular telephone, a smart phone, a tablet computer, a laptop computer, a wearable computer, a navigation device, a tracking device, etc.
The global positioning system (GPS) and other like satellite positioning systems (SPSs) may enable positioning and navigation services for mobile devices under certain conditions. For example, a mobile device located in an outdoor environment may perform certain positioning and navigation services based on acquired SPS signals transmitted by satellites. However, in certain instances, such as when they mobile device is located within an indoor environment, such satellite transmitted signals may be unavailable, e.g., due to signal interference.
Accordingly, in certain indoor environments, different positioning techniques may be employed to enable positioning and navigation services. For example, a mobile device located within certain indoor environments may seek to obtain a position fix (e.g., an estimated location) by estimating ranges to one or more terrestrial-based wireless network access points (APs) and/or other like wireless signal transmitting devices installed at known positions. Such ranges may be determined using known techniques based on one or more signal characteristics for one or more wireless signals acquired from and/or exchanged with such transmitting devices.
By way of a further example, such ranges may be determined by identifying a transmitting device (e.g., from a MAC ID address or other like information encoded in a transmitted message and/or otherwise determinable by an acquired wireless signal), and identifying a location of the transmitting device (e.g., from positioning assistance data and/or the like). Thus, for example, by measuring one or more characteristics of acquired wireless signal(s), such as, for example, a received signal strength (RSSI), a round trip time (RTT), just to name a few examples, an estimate of a distance (range) is from the mobile device to a transmitting device may be determined. Accordingly, with adequate range data available, a position fix for a mobile device may be determined using trilateration and/or other like known techniques. In certain instances, a position fix may even be based on a mixture of SPS pseudorange(s) and range(s) to one or more terrestrial-based transmitting devices.
Positioning assistance data may comprise a wide variety of information that may be useful to a positioning function enabled to provide and/or otherwise support certain positioning and/or navigation capabilities. For example, in the preceding examples various types of positioning assistance data may be applied in determining an SPS pseudorange and/or a range to one or more terrestrial-based transmitting devices. Hence, information provided within positioning assistance data may vary depending not only on the source of the wireless signals but also on the positioning function and its supported positioning and/or navigation capabilities. For example, positioning assistance data associated with terrestrial-based transmitting devices and/or other like terrestrial-based positioning services will clearly vary from one location to another.
In some instances, positioning assistance data may simply provide just enough information to obtain a rough position fix for a mobile device. For example, in certain instances a rough position fix for mobile device may be based on positioning assistance data indicating positions for APs nearby a mobile device. Thus, for example, a positioning function in certain mobile devices may select one of these APs (e.g. based on signal strength) and adopt the indicated location of the selected AP as its own rough position. In other example implementations, a positioning function may apply a more advanced algorithm to determine its position fix based on signal strengths, or other measured signal characteristics, associated with a plurality of APs and there indicated positions.
As may be appreciated, the amount of positioning assistance data may increase as additional information may be provided, e.g. corresponding to certain signal characteristics (e.g., encoded in various wireless signal propagation related parameters), and/or possibly even certain environment characteristics (e.g., encoded in various navigation parameters). For example, in certain instances positioning assistance data may comprise all or part of an electronic map and/or the like, which may correspond to an indoor environment and facilitate and/or enable location based services (LBS) and/or the like. In certain instances, (probability) radio heatmap data indicating expected RSSI, RTT values and/or the like associated with one or more APs may be provided. Further, in certain instances positioning assistance data may comprise routebability graphs, probability heatmaps, electronic maps for display, and/or the like or some combination thereof just to name a few examples.
As may be appreciated providing positioning assistance data to a plurality of mobile devices may, at times, be a complex undertaking given the plethora of positioning assistance data that may be available (some of which may be fairly voluminous), and the number of different positioning techniques which may be implemented in a variety of different types of mobile devices many of which may have their own specific requests, capabilities, limitations, etc. Indeed, in certain instances it may be exceedingly complex, costly, and/or otherwise inefficient (e.g., due to bandwidth limitations, etc.) to attempt to provide specific version(s) of positioning assistance data to various different mobile devices.